Studied herein is the mechanical behavior of FRP tube and steel tube double skin bridge columns (CDST), which have compared with the standard of high piers in the construction of highways recently, namely steel tube embedded concrete bridge columns. First of all, the strength interaction curve of CDST members subjected to axial force and bending moment is assessed. Particular emphasis is placed on the optimum arrangement of steel tubes in strength. It is concluded that the cross section with single and large size of inner tube is superior in strength and ductility compared to that with multiple inner relatively small tubes. Secondly, the compressive strength of CDST was studied experimentally, where the effectiveness of FRP outer tube compared to the ordinary steel tube used in CFT. It is understood that the thicker inner steel tube is eccential to confine the filled concrete, because of its severe biaxial compressive stress condition. It is also concluded that FRP tube with fiber direction in the circumference of tube can provide the good confinement to filled concrete and the strength of CDST can be equivalent or even better that that of CFT, with the significant reduction of the total weight.